Apparatus for the interconversion of sound and electrical impulses



Aug. 26, 1930. A. G. ZIMMERMAN APPARATUS FOR THE INTERCONVERSION OF SOUND AND ELECTRICAL IMPULSES Filed Oct. 8, 1927 Inventor: Arthur Glimmerman,

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Patented Aug. 26, 1930 UNITED. STATES PATENT oF-Hcr;

ARTHUR G. ZIMMEBIMLAN, OI SCHENEG'I'ADY, NEW YORK, ASSIGNOB TO Gm ELECTRIC COMPANY, A CORPORATION 01 NEWQYOBKJ urm'rns FOB 'rrm incriiaconvnnsron or soon!) AND morale Application filed October a, 1927. semi llo. 224,973.

- provision of an improved means for adjusting the mechanical relation between the various parts of such an apparatus.

Many' different types of apparatus for the interconversion of sound and electrical impulses have been provided in the past. Some of these apparatus comprise a coil which is arranged to be moved ina magnetic field either for producing sound impulses which are dependent on electrical impulses or' for producing electrical impulses which are dependent on sound or on the contour of a sound rec ord.

.When a coil is arranged to be moved in a magnetic field, difliculty is frequently encountered in producing and maintaining the proper spacing between the movable coil and the'pole members through which the magnetic field is produced. In accordance with my invention, this difliculty is avoided b the provisionof an improved means for a justing and maintaining the position of the coil in the magnetic fiel My invention will be better, understood from the following description when considered in connectionwith the accompanying drawings and its scope will be po nted out in the a pended claims.

Re erring to the drawings, Figs. 1 to 3 show different views ofa sound producing aparatus wherein my invention has been emodied. This apparatus comprises a conical diahragm l which is provided with a collar 2 or supporting a movable coil 3 and is mounted within a-casing 4. At its outer periphery this diaphragm is attached to a flexible memher 5 of velvet, or the like, which has its outer edge clamped between the casin 4 and a mem ber 6 by means of screws 7.

ith this arran ement, the diaphragm 1 is loosely held wit in the casing and is permitted to move freely in response to electrical impulsesap-' plied to the coil 3 or in response to sound impulses applied to the diaphragm.

The-coil 3 is sup orted in an-annular air es 8 and 9 of a magnet gap between the po 1 1 i which is supported on a base 10 and may be provided with a field coil 11. The casing 4 is clamped to the pole piece 8 by means of screws 12, and the position of the coil in the air gap is determined by tensile forces a plied to a plurality of cords 13 which are in gether at the center of the collar 2 and are otted tO- given one turn-around a cord 14, which is otherwise formed to. produce friction whereby the screws 15 are posi ively locked in any position to which they are turned. It will be apparent that this im roved means for ad justin the position 0 the movable coil has the a vantage that the adjustment is readily made from the front of the diaphragm where the spacing between the pole piece 9 and the collar 2'is readily observed. It will of course be understood that the cords 13 permit the coil 3 to move freely in a direction along the axis of the pole piece and coil.

The embodiment of the invention illustrated and described herein has been selected for the purpose of clearly setting forth the principles involved. It will beapparent,

however, that the invention is susceptible of being modified to meet the different conditions encountered in its use and I therefore aim to cover by the appended claims all modifications within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is 1. The combination of a casin a diaphragm attached to said casing t rough a' flexible connection, a coil mounted on said diaphragm, and means mounted on said casing for adjustin the osition of said c'oi from the front 0 said iaphragm. I

2. The combination of a casin a diaphragm attachedlto said casing t rough a Adjustment of the coil 3 the annular,

flexible connection, a coil mounted on said diaphragm, a plurality of cords connected to sai diaphragm, and means for controllin .the tension of said cords from the front 0 said diaphragm.

3. The combination of a casin 0. diaghragm attached to said casing t rough a exible connection, a coil mounted on said diaphra m, a plurality of cords connected to said 'aphragm for adjusting the position of said coil, means for controlling the tension of said cords from the front of said diaphragm, and means for producing a magnetic field intercepting said coil.

4. The combination ofv a c'as'in a diaphragm attached to said casing t rough), ,flexible connection, a coil mounted-on sald diaphragm, a bracket mounted on said casing a member threaded into said bracket, and flexible means connected to said diaphragm and arranged to be subjected to ,a tension controlled by said threaded member for adjusting the position of said coil.

5. An acoustical device comprising magnetic means Iprovided with an air ga a casing, a dia ra attached to sai casing through a exib e connection, a coil supported within said air gap b said diaphragm and means for adjusting t e position of sai coil in said air gap from the front of said diaphragm.

6. The combination of a casin a diahra m attached to said casingt rough a exib e connection, a coil mounted on said dia hragm, a pluralit of cords connectedto sai diaphragm, an means comprising a plurality of members threaded into said casmg and arranged to be turned from the front of said diaphragm, said cords being wound upon said threaded members for adjusting the position of said coil in said air gap.

In witness whereof, I have hereunto set my hand this 7th da of October, 1927.

R G. ZIMMERMAN. 

